Internet of things (IoT) scenarios are projected to involve many thousands of nodes operating in a large area, for example in a Smart City. IoT environments, such as wireless sensor network (WSN) installations, feature very challenging channel conditions. For example, IEEE 802.15.4 (ZigBee) communications use 16 channels in the 2.4 GHz ISM band that overlap with Wireless Fidelity (WiFi) and Bluetooth channels, which can lead to strong external interference. The scale of such installations also leads to congestion due to significant internal interference, for example among WSN nodes themselves. Thus a centralised, global management of the network may not be as effective or cost efficient as a more distributed, localised one.
Address management is an aspect of IoT networks that is particularly wasteful of resources. Addresses typically use fixed bit-widths. For example, a modern IoT installation requires 64-bit media access control (MAC)-level addresses, 16-bit network-level addresses and 128-bit Internet Protocol (IP) v6 addresses. Long addresses are used so that communication between every node of a network and every other node can be accommodated. Most of these addresses are allocated and/or checked centrally, for example at the network coordinator or router, and may be checked globally, for example to ensure MAC-address uniqueness. The upper layers of the IoT networking stack are required to allocate sufficient memory to accommodate a large number of these addresses, even when the actual deployment uses a much smaller range of addresses. During transmissions, some types of addresses are always quoted by the protocol stack, and for short range communications this is wasteful of resources, for example in terms of channel utilization and energy consumption.
In addition, nodes are essentially identified by such addresses. In particular, the intended recipient of a communication may be identified by a destination address. In some situations this may expose security-sensitive information to a potential attacker.
Preferred embodiments of the present invention seek to overcome one or more disadvantages of the prior art.